Spring latch lock

ABSTRACT

A lock ( 1, 30 ) is disclosed of the kind comprising: a box body ( 2 ) with a faceplate ( 3 ), a latch ( 4 ) co-operating with elastic means ( 5 ) adapted to keep the latch normally protruding from the faceplate ( 3 ) and with moving means ( 6 ) associated to a handle (M) to be actuated by the user and a mechanical adjustment unit ( 7 ) adapted to change the length of the portion ( 4   a ) of the latch ( 4 ) protruding from the faceplate ( 3 ). The mechanical adjustment unit ( 7 ) comprises a plurality of seats ( 8 ) made in the latch, ( 4 ), a contrast element ( 9 ) adapted to be received in each of said seats ( 8 ) and adjustment means ( 10 ) accessible from outside and acting on the contrast element ( 9 ) to constrain it in the corresponding seat ( 8 ) or release it therefrom.

The present invention relates to an improved spring latch lock.

It is well known that spring latch locks are devices to close and opendoors, main entrances, gates and the like, generally comprising a boxbody with a front plate and a sliding latch actuated by a handle.

Inside the box body there are the actuating mechanisms for the springlatch that can be reached and operated from outside through a handlewhich is inserted in a corresponding hole made on one or both sides ofthe box body.

The locks are arranged hidden inside a corresponding housing made in thethickness of the door, entrance or gate, the actuating handle of thelatch protruding from at least one side thereof.

Reliability of operation of the above mentioned locks is generallyrecognised as well as their functional limits with regard to thedifferent applications for which said locks may be intended.

A first recognised limitation is the constructional form of the latchhaving a fixed length so that its portion protruding from the faceplatecannot be modified.

This involves that the same lock cannot be used for differentapplications, when each application requires a different protrusion ofthe latch from the corresponding faceplate.

Thus, for instance, the same lock cannot be indifferently applied to adoor, a main entrance or a gate having different penetrations of thelatch in the frame. The same happens for instance in rooms provided withdoors identical to each other to which however different penetrations ofthe latch in the frame should be carried out whereby it is necessary touse locks with the same box body but having different performances withdifferent latch protrusion.

Moreover identical locks but having different latch protrusions are notinterchangeable.

In order to make easier closure of the door, main entrance or gate towhich the lock is applied the protruding end of the latch has a bevelthat during the closing operation is forced against the frame promotingthe elastic return of the latch inside the box body.

When the closing operation is ended, the latch comes out automaticallyfrom the box body and is inserted into the rabbet of the frame.

This involves the further drawback that the same lock cannot be appliedindifferently to door, entrances or gates having either right hand orleft hand closures so that a lock provided with a right hand bevelledlatch cannot be applied to doors with left hand closure and viceversa.

In order to overcome the above mentioned limitations, locks are madeprovided with adjusting means allowing to change the length of the latchprotruding portion and to rotate the latch so that the bevel is alwaysfacing the frame irrespective of the fact that the lock is applied to adoor, entrance or gate having either a right hand or left hand closure.

These locks, however, have the drawback that said adjustments aredifficult to be carried out.

More particularly the locks having the possibility to change theorientation of the latch bevelled portion relative to the frame, show agreater constructional difficulty because the latch must be made in twocoaxial parts that can be mutually blocked through screws, where thelatch protruding portion can be turned relative to the part lodgedinside the box body.

Another drawback consists in that, in order to change the latchprotrusion, the lock must be taken out from its housing, the box bodymust be opened in order to act on the adjusting means to define therequired protrusion of the latch.

After having carried out such an adjustment, the box body is againclosed, the lock is again assembled and it is also necessary to checkwhether the length of the protruding portion meets the requirements.

If the length of the protruding portion is not satisfactory, the abovementioned operations should be repeated.

Therefore, it is clear that such an adjustment is a long and difficultoperation.

Moreover such an adjustment must be carried out by persons having atdisposal proper tools and with specific professional skill.

The present invention aims at overcoming all the above mentioneddrawbacks. More particularly the first object of the invention is toprovide a lock in which it is possible to adjust the length of the latchportion protruding from the lock and the orientation of its shaped endrelative to the frame against which it rests, without taking out thelock from the housing of the door, entrance or gate to which it iscoupled.

Another object is that said adjustments may be carried out withoutdisassembling even a portion of the lock.

A last but not least object is that said adjustment does not requireintervention of specialised workers.

Said objects are attained by a lock of the kind comprising:

-   -   a box body;    -   a faceplate associated to said box body;    -   a latch co-operating with spring means adapted to keep it        normally protruding from said faceplate and moving means        associated to a handle that can be actuated by the user;    -   a mechanical adjustment unit adapted to modify the length of the        portion of said latch protruding from said faceplate, and is        characterised in that said mechanical adjustment unit comprises:    -   a plurality of seats made in the latch body;    -   at least a contrast element adapted to be received in each of        said seats; and    -   adjustment means accessible from outside and acting on said at        least a contrast element to constrain it in the corresponding        seat or release it from the seat.

According to a preferred embodiment each seat consists of a crescentlike recess receiving a corresponding contrast element consisting of acylindrical pin having its longitudinal axis arranged transversally tothe latch movement direction.

The seats made in the latch body are aligned according to tworectilinear directions parallel to each other and to the longitudinalaxis of the latch but offset at 180° one to the other.

According to this embodiment, by rotating the latch of 180° around itslongitudinal axis, its bevelled portion is oriented to the frameaccording to the rotation direction with which the door, entrance orgate is being closed.

Advantageously the lock of the invention makes easier the operations ofadjustment and control and faster the setting up operations carried outat the building yard before the premises are delivered.

Again advantageously in view of the simplicity of the adjustment to becarried out, said adjustment may be effected event by unskilled workerswith little experience.

Said objects and advantages will be better understood by reading thefollowing description of a preferred embodiment of the invention withreference to the accompanying sheets of drawings in which:

FIG. 1 is an isometric view of the lock of the invention;

FIG. 2 is a sectional view of a detail of the FIG. 1;

FIG. 3 is a partial longitudinal section of the lock of FIG. 1;

FIG. 4 is an isometric view of details of the lock shown in FIG. 3; and

FIG. 5 is a constructional modification of the lock of the invention.

The lock of the invention is shown in the isometric view of FIG. 1 andin the partial sectional view of FIG. 3 where it is generally indicatedwith reference numeral 1.

One can see that the lock comprises a box body 2 to which a faceplate 3is associated preferably but not necessarily through screws 2 a. The boxbody 2 and the faceplate 3 have coaxial and aligned holes through whicha latch generally indicated with numeral 4 is sliding, the protrudingportion 4 a of the latch being provided with a bevelled end 4 b.

Inside the box body two elastic means are associated to the latch 4consisting of a helical spring 5 coaxially arranged outside the latch,said spring keeping the portion 4 a normally protruding from thefaceplate 3.

Inside the box body 2 moving means generally indicated with numeral 6are provided, said means being associated to a handle M that can beactuated by the user to move the latch 4.

Still inside the box body 2 there is also a mechanical adjustment unitgenerally indicated with numeral 7, to change the length of theprotruding portion 4 a of the latch 4 relative to the faceplate 3 andtherefore penetration of the latch in the striker of the frame.

According to the invention said mechanical adjustment unit 7 comprises:

-   -   a plurality of seats 8 made in the latch 4;    -   at least a contrast element 9 adapted to be received in each of        said seats 8; and    -   adjustment means 10 accessible from outside and acting on the        contrast element 9 to constrain it in the corresponding seat 8        or release it from said seat.

More particularly with reference to FIGS. 2 and 4 the contrast element 9and the adjustment means 10 accessible from outside, are arranged in alodging block 11 arranged inside the box body 2, and provided with athrough hole 12 slidingly receiving the latch 4.

The lodge block 11 preferably but not necessarily has a parallelepipedalshape and is provided with a couple of slots 13 receiving the ends ofthe contrast element consisting in a cylindrical pin 9.

As to the adjustment means, they comprise a screw 10 whose head 10 a isarranged in a through hole 2 b, a part of which is made in the box body2 and another part in the faceplate 3, while the threaded stem 10 b ofthe screw is coupled in a threaded through hole 11 a made in the lodgeblock 11.

On the lodge block 11 and inside the box body 2 there is a striker wall11 b against which the end of the elastic means causing the slidingmotion of the latch 4 to be yielding is leaning. Said elastic meansconsist of a helical spring coaxially arranged outside the latch 4 andcontained between said striker wall 11 b of the lodge block 11 and thebox body 2.

As to the seats 8 made in the latch 4, one can see in FIG. 4 that theyconsist of a plurality of crescent like recesses arranged transversallyto the latch and aligned along two directions Xa, Xb parallel to eachother and to the longitudinal axis X of the latch 4.

The cylindrical pin 9 forming a contrast element, may be received in anyof said seats 8, in which it is held by the contact with the threadedstem 10 b of the screw 10.

With reference now to the moving means for the latch 4, generallyindicated with numeral 6, one can see that they comprise an annular body17 pivotally constrained inside the box body 2, in which a handle M tobe actuated by the user is coupled through a square hole 18.

The annular body 17 is provided with a projection 20 inserted in acorresponding seat 21 made in the latch 4.

A spring 22 circumferentially wound to the annular body 17 and arrangedwith an end 22 a against the box body 2, makes rotation of the handle Melastic so as to return the handle to the normal position shown in FIG.3 with the portion 4 a of the latch 4 protruding after each operation.

In operation starring from the condition of door closed, by rotating thehandle M, retraction of the protruding portion 4 a of the latch 4 intothe box body 2 in caused, allowing opening of the door.

On release of the handle, the elastic return of the helical spring 15causes the latch 4 to return to the starting position, with the portion4 a protruding from the box body 2 as shown in FIG. 1 or 3.

By an intervention on the adjustment means it is possible to rotate of180° the latch 4 around its longitudinal axis X to change orientation ofthe end 4 b of the protruding portion 4 a or to adjust the length ofsaid protruding portion 4 a relative to faceplate 3.

Indeed when the lock is arranged in the configuration shown in FIG. 3,the latch 4 is constrained to the lodge block 11 because the threadedstem 10 b of the screw 10 keeps the cylindrical pin 9 inside thecorresponding recess 8.

By acting on the head 10 b of screw 10 from outside through hole 2 b andby a screwdriver or similar tool, the screw 10 is unscrewed as shown inFIG. 2 so as to release the pin 9 that can move inside the slots 13 asit is no more constrained in the corresponding seat 8.

This allows to rotate the latch 4 of 180° turning its shaped end 4 b tothe frame with which it must be coupled.

Moreover, when the pin 9 is released, it is also possible to slideaxially the latch 4 so as to change the length of its protruding portion4 a relative to the faceplate 3.

When the required position is reached, the screw 10 is again tighteneduntil the pin 9 is again blocked in another seat 8 in a conditionsimilar to the that shown in FIG. 3.

According to the foregoing description it is clear that the lock of theinvention attains all the intended objects.

Indeed, the objects to be able to adjust the protrusion of the latch andorientation of its shaped end are attained through simple operationsthat are carried out from outside without disassembling the lock fromthe door, entrance or gate to which it is applied.

Moreover, simplicity of operations is such that they can be carried outalso by unskilled workers.

A constructional modification of the invention is shown in FIG. 5 andrelates to a lock generally indicated with 30 which is different fromthe above described lock for the addition of a bolt 31 of a kind knownper se associated to key means 32 to be actuated by the user.

In the constructional stage many modifications may be made to the locksof the invention in order to improve its operation or to make easier itsconstruction.

When said modifications or variations neither described nor illustratedin the drawings fall within the scope of the appended claims, theyshould be considered to be covered by the present patent.

1. A lock (1, 30) of the kind comprising: a box body (2) a faceplate (3) associated to said box body; a latch (4) co-operating with elastic means (5) adapted to keep the latch associated to a handle (M) to be actuated by the user; a mechanical adjustment unit (7) adapted to change the length of the portion (4 a) of said latch (4) protruding from said faceplate (3), characterised in that said mechanical adjustment unit (7) comprises: a plurality of seats (8) made in the latch (4); at least a contrast element (9) adapted to be received in each of said seats (8); and adjustment means (10) accessible from outside and acting on said at least a contrast element (9) to constrain it in the corresponding seat (8) or release it therefrom.
 2. The lock (1, 30) according to claim 1 characterised in that said at least contrast element (9) and said adjustment means are arranged in a lodge block (11) arranged inside said box body (2) and provided with a through hole (12) slidingly receiving said latch (4).
 3. The lock (1, 30) according to claim 2 characterised in that said elastic means consists of a helical spring (5) coaxially arranged outside said latch (4) and between said lodge block (11) and said box body (2).
 4. The lock (1, 30) according to claim 2 characterised in that said adjusting means comprise a screw (10) having an actuation head (10 a) arranged in a through hole (2 b) communicating with outside and made part in said box body (2) and part in said faceplate (3), and a threaded stem (10 b) coupled in a threaded through hole (11 a) made in said lodge block (11) and co-operating by contact with said contrast element (9).
 5. The lock (1, 30) according to claim 1 characterised in that said contrast element is a cylindrical pin (9) arranged with its longitudinal axis orthogonal to the longitudinal axis (X) of said latch (4).
 6. The latch (1, 30) according to claim 1 characterised in that said seats consist of a plurality of crescent like recesses (8) arranged transversally top said latch (4).
 7. The lock (1, 30) according to claim 6 characterized in that said recesses (8) are aligned to each other along two rectilinear directions (Xa, Xb) parallel to each other and to the longitudinal axis (X) of said latch (4) and are offset at 180°.
 8. The lock (1, 30) according to claim 1 characterised in that said moving means (6) comprise an annular body (17) pivotally constrained inside said box body (2) and coupled to said handle (M), said annular body (17) being provided with a protrusion (20) inserted into a corresponding seat (21) made in said latch (4).
 9. The lock (1, 30) according to claim 8 characterised in that a spring (22) opposing said box body (2) is associated to said annular body (17) so as to make elastic rotation of said handle (M).
 10. The lock (30) according to claim 1 characterised by comprising also a bolt (31) associated to key means (32) to be actuated by the user. 